Pipe string fill-up tool



Aug. 19, 196a 3 Sheets-Sheet 2 Filed June 22. 1967 Jar/"e1 V|/. Farr/09' fan INVENTOR.

s- 9, 9 J. w. HARRiNGTON 3,461,962

FIFE STRING FILL'UP TOOL 5 Sheets-Sheet 5 Filed June 22, 1967 Y m 5 M 9 M m Mm w 0 f y W m J Y\ e a I m a J o v r M i M W Z i l a a i .Cm. F v WW. w w. m J, v w 1,2, M? 1 ii 1 WK aw United States Patent US. Cl. 166-226 2 Claims ABSTRACT OF THE DISCLOSURE A fill-up tool is described comprising two telescoping tubular members for installation in a pipe string to permit the liquid in a well bore to enter the pipe string with a minimum of restriction, as the pipe string is lowered into the well bore. The two members are connected together by screw threads so that relative rotation of the members will move the members axially relative to each other. One member is provided with lateral openings through which the liquid in the well bore can flow into the tool and into the pipe string when the tool is in its open position. The other member is provided with seals to. close off the lateral openings, when the tool is in its closed position. The tool is opened by unscrewing the two members. This is the position of the tool as the string is run into the hole. When the pipe string has been lowered into the well bore to the desired depth, relative rotation of the members to make up the threaded connection between them will close the tool.

This is a continuation-in-part of patent application Ser. No. 585,006, filed Oct. 7, 1966, now abandoned and entitled Pipe Strong Fill-Up Tool.

This invention relates to a fill-up tool for installation in a pipe string above a restriction in the string that retards or prevents the entrance of liquid from a well bore into the pipe string.

When a pipe string containing a restriction, such as a float valve, is lowered into a well bore, and the well bore is filled with a liquid, such as drilling mud, it is the usual practice to periodically fill up the pipe from the surface. This is necessary where the well bore is deep, otherwise the hydrostatic head of the liquid could collapse the pipe. Stopping to fill up the pipe takes time, which increases costs. Further, this periodic filling of the pipe from the top traps air in the pipe. This air, when later circulated back to the surface through the annulus, can give a false indication of gas in the mud. This may cause operations to be suspended until it can be determined that gas is not actually present. Air in the mud may also reduce the reliability of downhole tools that employ pressure pulses, transmitted through the liquid in the drill string, to relay information to the surface.

As a pipe string is lowered into a well bore or hole filled with liquid, a volume of liquid at least equal to the volume of metal lowered into the hole must be displaced from the hole. Where the flow of liquid into the pipe is restricted, a substantially greater volume of liquid must be displaced. Therefore, there is a pressure build-up in the liquid in the hole each time another stand or joint of pipe is added to the pipe string and lowered into the hole. The greater the restriction to the flow of liquid into the pipe string and the faster the pipe is lowered, the larger the pressure build-up in the liquid.

These pressure build-ups or surges can force the liquid in the hole into exposed formations and, if high enough, break down the formations causing them to take liquid from the well bore at a substantially lower pressure than before. There are many reasons Why this is undesirable. Drilling mud or water forced into a producing formation can block or retard the flow of production fluid into the 3,461,962 Patented Aug. 19, 1969 "ice well bore, when it is time to produce the well. Also, formations that have been broken down may start taking drilling fluid at a pressure below the hydrostatic pressure of the fluid in the well bore opposite the formation. This may make it diflicult to maintain the circulation of drilling fluid or even to keep the well bore filled with fluid, making it necessary to take steps to seal off the formation. These operations are time consuming and expensive.

It is desirable, of course, that all of the equipment that restricts the flow of liquid into the pipe string be used. Most of this equipment, however, either functions only after the pipe string has reached the bottom of the well bore, or can have its function delayed for that length of time. Therefore, it is an object of this invention to provide a fill-up tool for installation in a pipe string above a restriction in the pipe string to the entrance of liquid from the well bore that will permit liquid from the well bore to enter the pipe above the restriction, while the pipe is being lowered into the hole, after which the tool can be closed to permit the restriction to function as intended.

It is another object of this invention to provide a fill-up tool for a pipe string that will provide a passageway through which the liquid in a well bore can enter the pipe as it is lowered therein and which will close the passageway when the portion of the pipe string above the tool is rotated relative to the portion of the pipe string below the tool.

It is yet another object of this invention to provide a fill-up tool for installation above a float valve in a pipe string equipped with a drill bit to provide an opening through which the pipe above the float valve can fill with the liquid from the well bore as the bit is lowered to the bottom of the well bore and which will close the opening when the bit engages the bottom of the well bore and the pipe is rotated.

It is another object of this invention to provide a fill-up tool for connection in a pipe string intermediate its ends comprising two tubular telescoping members that are movable by relative rotation between a first position where an opening in one of the members is opened to permit liquid to enter the pipe string from the well bore and a second or closed position where the first member closes the opening through the other member to restore the integrity of the pipe string.

These and other objects, advantages, and features of the invention will be apparent to those skilled in the art from a consideration of this specification, attached drawings, and appended claims.

The invention will now be described in connection with the attached drawings, in which:

FIGURES 1A and 1B are views, partly in vertical section and partly in elevation, of one embodiment of the fill-up tool of this invention in the first or open position, i.e., the position it is in when being lowered into a well bore to permit the liquid in the well bore to enter the pipe string;

FIGURES 2A and 2B are views, partially in elevation and partially in vertical section, of the fill-up tool of FIGURES 1A and 1B in the second or closed position, which is the position of the tool after the pipe string has been lowered into the well bore and the function of the tool is no longer required;

FIGURE 3 is a cross sectional view taken along line 3-3 of FIGURE 2A;

FIGURE 4 is a partial vertical sectional view on an enlarged scale of the means employed in this embodiment to lock the tool against the inadvertent opening thereof after it has been closed;

FIGURE 5 is a view, partly in elevation and partly in vertical section, of the preferred embodiment of the fill-up tool of this invention with the tool in its second or closed position; and

FIGURE 6 is a view, partially in elevation and partially in vertical section, of the tool of FIGURE in the open position.

As explained above, the fill-up tool of this invention is designed for use in a pipe string having a restriction that limits or prevents the flow of liquid from the well bore into the pipe string. In the embodiment shown, fioat valve 12 comprises this restriction.

The float valve is located directly above drill bit 13, which is connected to the bottom of the pipe string. The float valve includes cage 14 and flapper valve 15. The flapper valve is urged to the position shown in FIGURE 1B by a spring (not shown) so that the flow of fluid upwardly into the pipe string is prevented. The spring urges the flapper valve against valve seat 16 on the cage. Annular "alve element 17 of resilient material is carried by the flapper valve to sealingly engage the valve seat. The cage and flapper valve assembly of the float valve are located in float valve housing 18. Seals 14a are provided to seal between the cage and the valve housing. In the embodiment shown, the float valve housing also serves as a bit sub for connecting the lower end of the pipe string to drill bit 13. The drill bit also serves to hold the cage against downward movement in the float valve housing. Annular shoulder 18a holds the cage against upward movement.

In FIGURES 1-4, one embodiment of the fill-up tool of this invention is located in the pipe string directly above the float valve. It includes first member or mandrel and second member or housing 11. In this embodiment, housing 11 is integrally connected to float valve housing 18.

The first member or mandrel of the fill-up tool and the second member or housing are telescoping tubular members, i.e., one extends into the other and they can move axially relative to each other. The mandrel is connected to upper portion 19 of the pipe string. As explained above, housing 11 is connected to the lower portion of the pipe string, which includes float valve housing 18 and drill bit 13.

Means are provided to connect the first and second members together and for moving the members from a first position to a second position, when the members are rotated relatively in one sense. In the embodiment shown, mandrel 10 is provided with externally threaded section 20. Housing 11 is provided with internally threaded section 21. These threaded sections combine to provide a threaded connection bet-ween the two members that will move the first member axially into the second member, when the members are rotated relatively in a given sense. In the embodiment shown and preferably, of course, where the drill pipe is made up tool joints having righthand threads, the threaded connection employed in the tool is also a right-hand one.

One of the members is provided with an opening through which the liquid in the well bore can enter the pipe string as it is lowered in the well bore. In the embodiment shown in FIGURES l4, mandrel 10 has a perforated section 22 located above threaded section 20. The perforated section is provided with a plurality of openings 23 through the wall of the mandrel, as shown in FIGURE 3. The openings allow the liquid externally of the tool to flow freely to the inside thereof and thence into the interior of the pipe string. A large number of relatively small openings are used, instead of one or two large ones, to screen all solids from the liquid entering the pipe that are large enough to plug the bit nozzles when drilling is started.

Extending above the female portion of the threaded connection in housing 11 is sleeve 24. This sleeve is designed to enclose the perforated section of the mandrel, when the two members are in their second position, as shown in FIGURES 2A and 2B. Seal rings 25 and 26 are carried by the first member and located on opposite sides of the perforations to sealingly engage the sleeve and prevent further flow of liquid between the exterior of the tool and the inside of the pipe string.

Before being lowered in the well bore, the mandrel and housing of the fill-up tool are in the position shown in FIGURES 1A and 1B. For reference purposes this is called the first position. Float valve 12 will be closed, but as the drill pipe is lowered in the hole, the pipe string above the flapper valve will be filled by the liquid flowing through holes 23 in the mandrel. When the drill bit engages the bottom of the well bore sufficiently to hold the lower portion of the pipe string against rotation, the upper portion of the string can be rotated and the threaded connection between the mandrel and the housing will move the two members to their second position, as shown in FIGURES 2A and 2B. The fill-up tool is now closed and the float valve will prevent any more fluid from flowing into the pipe string from the lower end. In FIGURE 28 the float valve is shown open, the position it takes when fluid is being pumped down the pipe string.

Means are provided to limit the amount of relative rotation between the two members in the sense they were rotated to close the tool, so that, after the tool is closed, the pipe string can be rotated in the conventional manner to cause the drill bit to drill. In the embodiment shown, mandrel 10 is provided with downwardly facing annular shoulder 28 and housing 11 is provided with upwardly facing annular shoulder 30. When these two shoulders engage, as shown in FIGURE 2A, no further relative rotation of the two members, in the sense that they have been rotated relatively to cause them to move together, can occur. As stated above, this is usually right-hand rotation, since that is what is commonly used to rotate drill bits. If a left-hand string of pipe is used then a lefthand threaded connection is used between the two members.

Means are also provided to prevent relative rotation of the two members of the tool in the other sense, when in their second position. As shown in FIGURE 4, mandrel 10 is provided with drilled hole 32 below its threaded section. The hole extends transverse the longitudinal axis of the member. Located in the hole is pin 34 and coil spring 35, which urges the pin out of the hole. When the members are in the first position, as in FIGURES 1A and 1B, pin 34 serves to engage the lower thread on the female portion of the connection to limit the distance the two members can be unscrewed. When the members have been moved to the second position the pin will snap into recess 36a in bushing 36. The bushing is located in tapped hole 37, which extends through the side wall of housing 11. Engagement of the pin and the bushing hold the two members against relative rotation in either direction to insure that the threaded connection between the two does not back off inadvertently, while the tool is in the well bore. To reduce to a minimum the length of pin 34 that is unsupported, the bore of housing 11 at the location of bushing 34 is reduced, as shown.

To add stability to the threaded connection between the two members, in addition to the interengagement of shoulders 28 and 30, mandrel 10 is provided with a downwardly extending pin section 46 of reduced outside diameter. The pin is received in lower section 41 of housing 11. The clearance between pin 40 and the bore of section 41 should be such that the pin can freely enter the bore and yet help to stabilize the two members against bending independently.

Seal ring 26 provides a fluid seal between the two members above the threaded connection when the members are in either position. Seal ring 46 is located on pin 40 to sealingly engage the bore section 41 of the housing and provide a fluid seal between the members below the threaded connections, when the members are in either position.

Bushing 36 is provided with port 3612 to provide an escape route for the fluid trapped by seal rings 26 and 46 between downwardly facing annular shoulders 43 on the mandrel and upwardly facing shoulder 44 on the housing, as the two members telescope.

In the embodiment shown, the fill-up tool transmits the drilling torque and weight imposed on drill bit 13. To improve the torque transmitting abilities of engaging shoulders 28 and 30, they are cut so that their engaging surfaces are on matching helix angles. In this way, shoulder 28 can be provided with surface 151 and shoulder 30 with surface 151, which are parallel to the longitudinal axes of the members and which have lengths equal to the pitch of the helix angle of the spiralling portions of the shoulder surfaces. The engagement of surfaces 150 and 151 improves the torque transmitting efliciency of the connection between the two members.

The preferred embodiment of the fill-up tool is shown in FIGURES and 6. It includes first member or mandrel 50 and second member or housing 51. The mandrel is adapted to be connected to the upper portion of the pipe string (not shown). Housing 51 is connected to lower portion 52 of the pipe string. Mandrel 50 is provided with externally threaded section 53. These male or external threads mate with the internal or famale threads on threaded section 54 of the housing. Above threaded section 54 on the housing is sleeve section 55. An internal annular groove is located adjacent the upper end of sleeve section 55, in which is located seal ring 56. This seal ring is located to seal between the housing and wear sleeve 57, positioned on mandrel 50 above threaded section 53.

Located in bore 51a of the housing and below threaded section 54 is second wear sleeve 58. This sleeve is located for its inside surface to slidingly engage seal ring 59 carried by tubular section 50a of mandrel 50 located below threaded section 53. Preferably, the clearance between wear sleeve 58 and section 50a is at a minimum. This is desirable because it adds lateral stability to the tool, when in the closed position. A close fit between wear sleeve 57 and the inside of sleeve section 55 also improves the lateral stability of the tool in the closed position. Wear sleeves 57 and 58 are held in the desired position in sealing engagement with the mandrel and the housing, respectively, in any convenient manner. In one commercial embodiment, a force fit is used. The sleeves should be made of a material, such as bronze, which will not tend to gall when it slides on steel. This allows the clearance between the members to be reduced to a minimum to obtain the desired stability.

A plurality of lateral openings 61 extend through the wall of housing 51 below wear sleeve 58. It is through these openings that fluids can enter the tool as the pipe string is lowered into the hole and the tool is in the open position, as shown in FIGURE 6. Preferably, these openings are elongated slots or ports as this shape seems to reduce the tendency of the ports to become plugged with solids contained in the drilling fluid. In this embodiment, in the same way as described above in connection with the embodiment shown in FIGURES 1 through 4, right-hand rotation of the pipe string to cause relative rotation between the members will cause them to telescope to the closed position shown in FIGURE 5.

In the closed position, two seals are employed to prevent the flow of fluid between the inside and outside of the tool through openings of ports 61. The first is seal ring 60. This is a pressure energized seal located in annular groove 60a.

To provide an accessible groove for seal ring 60, the lower end of housing 51 is threadedly connected to housing sub 66, which connects the housing to the lower portion of the pipe string. Seal ring 67 provides a seal for the threaded connection. The internal diameter of the housing above the threads is increased to provide downwardly facing annular shoulder 68. This shoulder and upper end 62 of the sub are spaced apart to provide annular groove 60a in which seal ring 60 is located. The upper end of the sub is bored to a diameter large enough to receive the lower end of the mandrel to permit seal ring to sealingly engage the outside surface of the mandrel below the openings when the tool is closed.

The other seal is a metal-to-metal seal formed between the mandrel and housing sub 66. The valve seat for this seal is annular surface 69 formed by boring the end of the housing sub to receive the mandrel. The valve element is lower end 63 of the mandrel, which engages seat 69 and forms a metal-to-metal seal between the end of the mandrel and the housing, when the tool is closed. When the tool is closed, of course, upwardly facing annular surface 64 on the upper end of the housing engages downwardly facing annular shoulder 65 on the mandrel to provide a torque transmitting connection between the members. Therefore, the length of mandrel 57 below shoulder 65 and the distance below the upper end of housing 51 to seat 69 should be closely held to the desired dimensiOns. When determining these distances, however, it should be kept in mind that after annular shoulders 64 and 65 engage, additional rotation between the members can occur if suflicient torque is placed on the members. This occurs frequently when the tool is used to transmit torque to a drilling bit. Then the torque may be sufficient to stretch the mandrel between the threads and the shoulders and compress the housing. This additional make up will force the valve element 63 on the lower end of the mandrel further into the housing and into tighter engagement with seat 69. This metal-to-metal seal not only provides additional security against leakage through the tool, but it also helps improve the lateral stability of the tool by anchoring the lower end of the mandrel against lateral movement relative to the housing.

Means are provided for limiting the distance mandrel 50 can be withdrawn from housing 51. In the embodiment shown, mandrel 50 is provided with groove 70 just below threaded section 53. Groove 70, preferably, is semicircular in cross section. The housing is provided with arcuate surface 71, just below its threaded section. Preferably, the radius of curvature of arcuate groove 71 and semi-circular groove 70 are the same. Positioned in groove 70 are a plurality of balls 72 having a diameter such that they substantially fill groove 70 and protrude from the groove far enough to fully engage arcuate annular surface 71. With this diameter, they cannot escape from groove 70 into the space between the mandrel and the bore of the housing. The balls then will engage arcuate surface 71 and prevent further upward movement of the mandrel relative to the housing. The grooves in effect will act as races of a ball bearing and considerable torque can be applied to the mandrel, in the direction to move it further out of the housing, without causing damage to the mandrel or the housing or without causing it to stick so that a large amount of torque will be required to rotate it to the right to close the tool.

Balls 72 can be positioned in groove 70 through lateral opening 73 in the wall of the housing. This opening is then closed by pipe plug 74. A small vent hole is located in plug 74 to keep from creating a pressure lock between seal 56 and seal 59, as the tool telescopes between its first and second, or opened and closed, positions.

It will be seen from the foregoing that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A fill-up tool for connecting into a pipe string having a restriction limiting the amount of liquid in the well bore that can enter the pipe string as it is lowered into the well bore, said fill-up tool comprising, first and second telescoping tubular members relatively movable axially between a first position and a second position, the first member having one end for connecting to the portion of the pipe string extending above the fill-up tool, the second member having one end for connecting to the portion of the pipe string below the tool and an opening through which the liquid in the well bore can enter the pipe string as the tool is lowered into the well bore by the pipe string and the members are in the first position, mating male and female threads on the first and second members, respectively, connecting the first member to the second member and for moving the members axially from the first position to the second position when the first member is rotated relative to the second member in one sense, and means for closing the opening when the members are in the second position to stop the fiow of liquid into the pipe string through the opening including a. tubular unthreaded lower section of the first member, located below the male threads on the member, to move past the opening in the second member when the members move from the first to the second position, a seal ring located below the opening in the second member to engage the lower section and seal oil? the opening, said second member having a section below the opening into which the lower end of the male member extends, having a diameter only slightly larger than the lower section, said first and second members further having oppositely facing annular shoulders above their threads that engage when the members are in their second position and combine with the lower section of the first member and the close fitting bore of the second member in which it is located to provide lateral stability to the tool when in the second position.

2. A fill-up tool for connecting into a pipe string intermediate its ends comprising first and second telescoping tubular members, mating male and female straight threads on said first and second members, respectively, connecting the members together for axial movement of the first member into the second member when the members are rotated relatively in one sense and for moving the first member axially out of the second member when the members are rotated relatively in the other sense, means limiting the movement of the first member out of the second member to a first position and means limiting the movement of the first member into the second member to a second position, said second member having at least one lateral opening through which liquid in a Well bore can enter the tool and a pipe string in which it is connected when the members are in the first position, said opening being positioned below the first member when the members are in their first position, said first and second members having downwardly and upwardly facing annular shoulders, respectively, that engage when the members are in their second position to transmit the torque imposed on the first member by the pipe string to the second member, when the pipe string is rotated in the one sense, said first member further having a second downwardly facing annular shoulder on its lower end, said second member having an annular sealing face located below the opening in the second member to engage the second downwardly facing annular shoulder on the lower end of the first member and provide a seal therebetween to prevent the flow of fiuid through the opening.

References Cited UNITED STATES PATENTS 1,508,230 9/1924 Lewis 175-317 X 2,905,250 9/1959 Talbott 166226 2,906,493 9/1959 Whitener 175317 X 2,944,794 7/1960 Myers 175-317 2,984,451 5/1961 Conrad 166226 X 3,058,534 10/1962 Keithahn 175-3 18 3,100,538 8/1963 Sanders 166237 3,130,788 4/1964 Cochran et a1. 166237 X OTHER REFERENCES Baumeister, Theodore: Mechanical Engineers Handbook, New York, McGraw-Hill, 6th Ed., 1958, pp. 8-125.

CHARLES E. OCONNELL, Primary Examiner IAN A. CALVERT, Assistant Examiner U.S. Cl. X.R. 

